INVESTIGADORES
RELVA Maria Andrea
congresos y reuniones científicas
Título:
Do mallines explain sociality in colonial tuco-tucos?
Autor/es:
TAMMONE, M; LACEY, E.; RELVA, M. A.
Lugar:
Mendoza, Argentina
Reunión:
Congreso; The 10th International Mammalogical Congress; 2009
Institución organizadora:
IADIZA, CONICET; SAREM
Resumen:
Among mammals, sociality (defined as group living) typically arises due to natal philopatry. Current theory suggests that philopatry occurs when suitable habitat is sparse or patchily distributed, making it difficult for individuals to disperse from the natal area. Colonial tuco-tucos (Ctenomys sociabilis) are subterranean rodents that are endemic to a 700 sq km area of Parque Nacional Nahuel Huapi in southwestern Argentina and that are listed by the IUCN as Critically Endangered. Unlike most other species of ctenomyids, colonial tuco-tucos are social, with each burrow system (colony) shared by multiple adult females. Previous studies of this species have suggested that C. sociabilis is restricted to mallines, which are mesic patches of Patagonian habitat characterized by a community of hydrophilic plant species that is distinct from the surrounding arid steppe grassland. The irregular spatial distribution of mallines coupled with their high level of productivity is thought to have favored natal philopatry and hence group living in C. sociabilis. To test the generality of this hypothesis, we quantified the structure and composition of vegetation associated with 57 colonies of C. sociabilis from 3 different populations (1 low and 2 high elevation sites) located at the extremes of the species’ geographic range. These populations differed significantly with respect to both floral structure and composition, with animals at the 2 high elevation sites tending to occupy arid, shrub-like habitat while animals at the low elevation site occurred primarily in mallines. Anecdotal observations indicated that C. sociabilis lives in groups at all 3 sites, suggesting that an association with mallines is not a general explanation for sociality in this species. Analyses of the spatial occurrrence of mallin and shrub habitats are needed to determine if the apparently patchy distribution of both vegetation types contributes to philopatry and group living by colonial tucotucos.